<!DOCTYPE html>
<style>
#container {
    overflow: scroll;
    width: 400px;
    height: 300px;
    background: linear-gradient(black, white);
    background-attachment: local;
}

#bloat {
    height: 1000px;
}
</style>
<div id="container">
    <div id="bloat"></div>
</div>
<script>
    document.getElementById('container').scrollTop = 1000;
</script>
